I am considering a transportation build, which means small deck, small enclosure, and 1 battery if possible. I am hoping to take this to Germany (I know, German Esk8 laws, but I’m willing to take the risk) and for air travel the battery must be below 99 Wh. I found a battery with below 88.8 Wh, but it has 30C marked on it. I am not as knowledgable about the effects of Coulombs as I am when it comes to Volts or Amps. Here’s the link: http://www.hobbyking.com/hobbyking/store/__16225__ZIPPY_Flightmax_8000mAh_3S1P_30C_Lipo_Pack.html Would 30C be doable? What would potential problems be? Any thoughts on this would be greatly appreciated
hope this isn’t too remedial.
Your C will only affect your charge rate, and discharge rate in Amps. To determine discharge rate (or ability to discharge at a certain amperage) - take your Ah x C = amp discharge capacity. usually they will state “constant” and “burst”.
So this pack (which i have - working well after over a year), will discharge 30C (30x8Ah) 240A continuous, and 40c (40x8Ah) 320A burst. I typically want a minimum of 100A continuous, as you want to only use a portion of the continuous discharge capability to extend pack life. I’ve measured 45-60A peak usage on these in dual setup.
3s is not going to work well - i would at least get 6s (two of these) or get a larger 6s battery. You would usually get batteries in teh # series you need after picking your ESC. Most hobby ESC’s max about 6s capability. More than 6s gets expensive. Well known options in this range are the FVT/XERUN and several others. For more than 6s i’d recommend either DIYes options or VESC (my preferred).
HTH!
Thanks for the info @sl33py , it helps a lot! I’ll try and find a battery for 5s or 6s thats under 100Wh if i can, do you have any recommendations?
I’m a fan of two smaller/thinner batteries vs a single thicker one:
it’s lower profile both for ground clearance, and less visible when riding (vs a big ass box below deck).
Here’s an example (a poor one - my first test setup using painters tape to secure electronics) of single:
vs two:
So, if your limitation is 99Wh - your max will be two 4500mAh batteries (3s/11.1v nominal). To determine Wh of a battery: (mAh)(V)/1000 = (Wh) or simplified a 4500mAh battery is 4.5Ah, so (Ah)(V)=Wh. So dual 4.5Ah = 99.9Wh (4.5Ah * 11.1v = 49.5 x 2 = 99.9Ah).
In that case, i would get a pair of the smallest/thinnest/stealthiest 4500mAh batteries i could find. Here are some to look at: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10283 (~$30 ea x 2 = $60) http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=63415 (~$27 x 2) http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17247 (~36 x 2)
or you can get a single 6s like this - just note instead of 23-30mm “thick” (C dimension), they are 44mm thick.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11933 (~$60 ea)
[quote]Capacity: 4500mAh Voltage: 6S1P / 6 Cell / 22.2V Discharge: 25C Constant / 50C Burst Weight: 687g (including wire, plug & case) Dimensions: 168x49x_44mm_ Balance Plug: JST-XH Discharge Plug: 4mm bullet-connector[/quote]
So while a single is enticing for simplicity - it will be nearly twice as thick. so from the side more visible.
A super stealth setup would be a small enclosure like psychotiller makes - a single or dual batteries and ESC all enclosed. Thinner and able to fit two 4500mAh batteries would give you low profile and 99Wh to maximize range.
I would not go below 6s. At 99Wh you should be able to expect some decent range.
A rough rule of thumb (will definitely depend on your riding style, weight, and hills vs flats) is 10Wh = 1km. So your 99Wh should get you ~10km/6mi.
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Here we are! Two of these ought to cover it. Thanks for the help! http://www.hobbyking.com/hobbyking/store/__10283__Turnigy_4500mAh_3S_30C_Lipo_Pack.html
I’m trying to figure out the limitations as well, I’ve found this chart from FAA. Your thoughts? Max 160Wh and 2 batteries means 320Wh to me but you’ll have to be able to split them.
The thing is based on that chart you have to have airline approval to go above 1 battery and 99Wh. I doubt they’d ever accept it, probably easier to just stick with 99Wh
So If I made a new sticker on my space cell that’s stating it’s 99Wh I should be fine? Who’s ever going to test that ^^
Yep you’d probably be fine… I don’t think they have any way to test it
Someone might look it up online real quick and double check. If it’s wrong, you might be in a world of trouble depending on who’s checking you.
Well I plan to keep it at 99Wh for travel anyways… Shouldn’t be a problem if we don’t lie about it
I want to wire up 3 of them battreys in series Will the focbox handle and can i use 14awg 4mm (that would mean changeing the 5.5 to 4mm)